In North America, this spring-flowering annual weed occurs mostly in southeastern states. It has become widespread and locally abundant, especially in damp pastures. It was first collected from Ky. in the 1970s (Faller 1975; Browne & Athey 1976; M). R. sardous has a relatively high content of anemonin, which is a dimerization protuct of the more toxic lactone "protoanemonin" (Neag et a. 2018). These and various other compounds in Ranunculus have physiological effects on mammals, generally reducing consumption as a bulk food. However, there has been much medicinal use by humans (Neag et al. 2018).